Ring laser gyroscopes typically include a solid block of dielectric material having a plurality of interconnected passages that are arranged in a closed loop to create a resonant cavity, with mirrors positioned at the intersection of each of the passages. In some implementations, a lasing gas is contained within the resonant cavity, and electrical potentials are applied to the lasing gas to generate counter-propagating laser beams in the resonant cavity. In other implementations, a solid state gain medium is added to one of the mirrors in the resonant cavity to generate the counter-propagating laser beams, without use of the lasing gas. For example, a few half-wavelengths of neodymium doped silica can be used to create the laser gain medium for the resonant cavity.